Industrial robots are used for machining in mechanical engineering. This trend is associated with an increase in the geomet-ric complexity of parts and wider kinematic capabilities of industrial robots in comparison with classical CNC machines. The article analyzes the technological capabilities of using industrial robots in finishing machining operations, and pro-vides the reasons for limited robots introduction Schemes of construction of technological operations are given: "part in hand" and "tool in hand". The factors influencing the choice of the preferred machining are studied. The areas of effective application of passive and active adaptation tools are given. The article provides two main reasons for possible vibrations under robotic manipulation: e.g. low rigidity of the industrial robot structure and shape errors effect in the previous opera-tion. The problem of developing a sustainable code conversion for the amount of material removal is discussed. The problem statement is due to the fact that the model of the cutting process varies greatly depending on the cutting conditions. Force control work makes it possible to take into account the rigidity of the robot without sacrificing the running accuracy in six coordinates. The article discusses the use of a neural network and a genetic algorithm in the development of a robotic pol-ishing operation for a flat surface within limited access constraints. The authors of the article have developed a postproces-sor for controlling an industrial robot in case of variable tool overhang and uneven tolerance. Special technological equipment has been designed and manufactured for this purpose. Experiments on testing of the developed algorithmic and software have been conducted in the laboratory "Industrial Robots and Automation Tools"
the article discusses the problem of technological stability assurance of deep drilling operations performed on automated equipment – multipurpose CNC machines. A group of large-sized forging parts and pressing blanks is viewed. It is shown that using a set of special drills and counterboring tools instead of universal horizontal milling machine makes it possible to avoid making special tools and contributes to the improvement of cutting modes, but the problem of stability assurance re-mains. A study of the hardness of such forgings revealed the unevenness of this characteristic in various parts of the work-piece. Despite the fact that, from the point of view of statistics, the totality of experimental data is homogeneous and the flow process of metallurgical forging production is stable, the revealed hardness variability turns out to be very sensitive for the subsequent stage of machining, namely for its special type like deep drilling. Experimental studies of chip formation in hole-making operations have proved that. It is noted that the task of managing the operability of tools and the quality of the re-sulting surfaces should be solved both at the stage of process design and just within operations. The latter can be solved through adaptive control, which is implemented on modern mass-produced multipurpose CNC machines in terms of the op-erating cutting power, which does not require retrofitting an automated machine-tool fleet for machining sites. The ra-tionale for the selection of factors and their variation levels in the construction of regression models used for design process and adaptive control of deep drilling operations on multipurpose CNC machines is given.
The use of ultrasonic dimensional technologies to reduce technological residual stresses occuring under machining of non-rigid blanks in parts made of alloys with a low melting point is one of the most effective methods for manufacturing structurally complex parts. The main methods of using modulated ultrasonic vibrations (UsV) and their advantages when introduced into the machining zone during milling operations are viewed. Special attention is paid to the use of various types of UsV modulation to increase the efficiency of reducing technological residual stresses by involving dislocation segments of different lengths in the relaxation process when machining thin-walled non-rigid aluminum alloy blanks. The technological residual stresses were evaluated using the Seton-ARM measuring and computing complex. Phase changes in the surface layer of aluminum parts of the Rikor–7 X-ray measuring complex. The data obtained was processed on a computer using the MD-10 program. The UsV modulation was carried out using an original installation that includes a ultrasonic generator, a PC that generates a modulation signal into two channels: on the first channel, a sinusoidal one, on the second, a sinusoidal, square or triangular one with a phase offset of 0 or 90 degrees. Studies measuring the positions of the treated surfaces of thin-walled parts using the Renishaw OMP40 contact sensor have shown that their twisted effect decreases by 30...40%. There was no significant difference in the results of processing workpieces made of deformable aluminum alloys D16 and AK6.
A number of works devoted to the technological heredity of products obtained by additive technologies are analyzed. One of the main disadvantages of additive manufacturing methods for plastic and metal objects is the high surface roughness caused by the layering technique. Based on the analysis of the sources, the directions of development of ultrasonic post-treatment of products have been determined. It can significantly reduce surface roughness. Studies have been conducted on the finishing of plastic products in a solvent evaporation obtained by ultrasonic spraying. The technique makes it possible to adjust the size of the droplets and the speed of their movement by changing the modes of ultrasonic treatment. Evaporating treatment schemes for products of different sizes are proposed. As a result of experimental studies, it has been established that evaporating treatment of a solvent obtained by ultrasonic spraying allows significant reduction of the surface roughness. Various types of ultrasonic treatment have been proposed for parts obtained by selective laser melting to improve the surface quality of products. Comparative studies have been conducted on the effects of cavitation-erosion and cavitation-abrasive treatment, as well as ultrasonic surface plastic deformation aimed at reducing surface roughness. It was revealed that all mentioned types of ultrasonic treatment contribute to surface roughness decrease in the following ways: cavitation-erosion by 33 %, cavitation-abrasive by 43 %, ultrasonic surface plastic deformation by 52 %.
Based on the concepts of the physical-chemical mechanics of contact interaction, a materials science analysis of these factors effect on the structure and wear resistance of an antifriction alloy under friction in surface-active lubricating media has been carried out. Tests of the bronze BrA5 − steel 45 friction pair were carried out on a reversible sliding friction machine under conditions corresponding to the operating modes of heavily loaded friction units. The role of physical-chemical factors related to the surface activity of the medium was revealed using an experimentally obtained set of macroscopic integral criteria (phenomenal indicators of friction and wear) and microscopic (microstructural) criteria (physical broadening of X-ray lines, the period of the crystal lattice, the elemental composition of the surface layer of the material of the contact deformation zone), determined using the X-ray diffraction method. It is shown that the formation of a wear-resistant structural state of a material in a surface-active lubricating medium is based on two structure-forming processes. The first one is connected with the formation of a stationary macroscopic diffusion flow of atoms of alloying elements and their transition into a lubricating medium, which leads to the creation of a surface plasticized layer, and the second process is a decrease in the density of dislocations in the material of the deformation zone, which indicates the effect of plasticizing the material (reducing its yield point stress). As a result of these processes, the material of the contact zone differs significantly from the initial one in terms of stress state, microstructure, and mechanical properties. The use of lubricants containing surfactants in tribounits contributes to the formation of a wear-resistant structure in the antifriction material.
